Process of treating ores.



E. B. PARNELL.

PROCESS OF TREATING ORES.

APPLICATION FILED NOV. 26, 1909.

962,383., Patented June 21, 1910.

WI TN 55 s 55 ELIZABETH BARNSTON PARNELL, OF CARSHALTON, ENGLAND.

PROCESS OF TREATING ORES.

Specification of Letters Patent.

Patented June 21, 1910.

Application filed November 26, 1909. Serial No. 529,977.

To all whom it may concern:

Be it known that I, ELIZABETH BARNSTON PARNELL, a subject of His Majestythe King of Great Britain, residing a Carshalton, in the county ofSurrey, England, have invented a new and useful Improved Process ofTreating Ores, of which the following is a specification. I

This invention relates to an improved process of treating ores eitherfree or complex and is particularly applicable to ores containlng goldand silver in conjunction with other metals, such for instance ascopper, which metals can be converted into a solution such for exampleas a sulfate.

The main feature of the present inven-' tion consists in the treatmentof an ore by boiling with a hot blast in water with or without acid forthe purpose among others of removing in such a case the sulfates andcausing them to pass into solution. As a part of such process the ore tobe so treated is preferably first roasted and during such roasting ispreferably treated by an electric current the roasting bringing it intosuch a condition that the iron in it may be removed by a suitableelectric separator or otherwise prior tothe further treatment for othermetals.

Other features of the invention will be set out hereinafter.

According to the preferred form of carrying out the process according tothe invention, the ore after crushing and sieving to obtain a uniformityin fineness, is first deprived of'its arsenic (if it contain any) byfumin off same to a condenser at a temperature 0 550 to 700 F. duringwhich process a free air supply must be maintained. to prevent anyarsenic falling back upon the ore, and forming compoundswith the metalsthereby and to insure that it passes to the means, whatever they may be,for condensing same.

The removal of arsenic if necessary is conducted in a roasting furnaceof some suitable kind. This furnace may be the same one as that used forsome of the subsequent steps of the process, for which latter steps itis preferably provided with electric conductors 1n the form for instanceof plates, bars or rods, from which when current is applied to them aconstant mild current may be passed through the ore during roasting. Theroasting .is facilitated if a small portion of the charge is used as itcomes from the rock breaker as the larger piecessay inch cubes orthereabout-serve to allow of air reaching the ore.

For the purpose of thoroughly subjecting the ore to the current if suchis used it may be either rabbled on to or thrown upon the conductors (asthe case may be) of the roasting furnace (which may be a stationary ormovable one), or the body of the furnace if ofconducting material may beconnected up to an electric supply. During the period that it is in thefurnace the ore in a treatment for sulfates is sprayed with sulfuricacid and water or with liquor obtained from sulfurous fumes saved fromthe condenser, after removal of the arsenic. The constant mild currentand the heat combine to convert the iron ,in such a case first to aniron sulfate and as the roast is prolonged effect the destruction ofsuch sulfate and the conversion of the ore into a suitable" conditionfor the removal of the iron, the heat also at a later stage converts thecopper to the form of sulfate. If. zinc be present the heat should notbe unduly raised as a small quantity may thereby be fumed off to thecondenser. The or is then discharged and passed over any suitable.electric or other concentrator which will recover all the iron inaproximately the condition of iron sand. This is more fully secured whenthe roasted ore is first cooled down.

If zinc is present in the ore it can be recovered after the iron sandhas been extracted by passing the ore a ain over the electricconcentrator with a di erent current or two concentrators difi'ering incurrent may be used in steps for the recovery of the iron and zincrespectively. I

The recovery of the copper is effected when the treatment has reachedthe stage described, by treatment of the sulfate of copper. For thispurpose care must be taken during the treatment in the furnace to form aperfect sulfate to the extent of one hundred er cent. of the metal asthis is necessary if full recovery of the V recious metals is to besubsequently obtains This formation of a sulfate of copper in thefurnace varies with the time of the roast and the temperature, forexample, a copper ore from an Irish mine can be sulfated at atemperature of just over 1000 F. so that up to one hundred per cent. ofthe metal can be sulfated in say three and a half hours, while, anauriferous Queensland copper ore will at a temperature of over 1200 F.requlre a roast of from seven to eight hours to give a hundred per cent.sulfation. The

ore has now had its iron removed and its copper brought to the form ofsulfate. It is now fed into a suitable vessel hereinafter referred to asan agitator and suificient water is added containing say two tofive percent. of a suitable acid such as sulfuric acid 'to convert the ore intoa thin mud, a hot blast is introduced and in a few minutes, more watermay be added. This hot blast may be obtained from a hot stove and fan,

or from pipes in the furnace and a fan or otherwise. The charge isthoroughly boiled by the blast for which purpose such blast should be ata high temperature and is-also agitated by its action which may becontinued for about half an hour in order to bring its cop er intosolution. The liquor is then run 0 into tanks in which the pure copperis recovered in some suitable way as by electro-deposition. The oreremaining in the agitator is then thoroughly washed with water. c

When the ore is clean any remaining liquor is exhausted fromtheagitatorf(or the ore may be removed to a filter press) and then ifprecious metals are present a cyanid or other suitable solution anduicksilver if the metals present are coarseb is introduced into-thecharge in the agitator, at which stage oxygen or enriched air issupplied to the agitator from a as separator or otherwise m such as issuitable to assist the solution of the precious metal. The hot blast ismaintained during this dissolvin of the precious metals and the cyanidor like solution containing same is drawn off and treated in any knownway.

Some. ores such as zinc-silver will give better results when the iron isfirst removed and :the remaining, ore is.converted v into chloridsinstead of into sulfates. fSuch ore is first treated in the furnace .byroasting.

and also if desired b r I is thenseparated' an the ore is returned tothe furnaceor passed to a second furnace and is heated with salt inaddition to the sulfuric acid to convert the metals into chlorids,otherwise the rocess is' the same as for the production 0 the coppersulfate;

As the coppersulfate would rapidly destroy an ordinary! steel or ironagitator vessel a vessel whic cannot be destroyed bychem- .ica'l actionmust be employed. The agitator body1 for this purpose may be made ofwood,- or t e body may be of iron or, steelefiectivelypainted orotherwise protected from I i the copperliqu'or. Thebodyvshouldfpreferably be provided with alinln .set inga suite ablecementyor' in wood; wiichjliningiis preferably bf glass orearthenware-tiles. 3 If wood is used, the pores must, be filled with (orcyanid.

roportlon the current, the iron' silica, or other innocuous compositionwhich will protect the wood from the destructive action of the acid coper liquor.

To more clearly expl un the invention reference is made to theaccompanying drawing which illustrates suitable t pes of apparatus, asan example only of what may be used, but I make no claim to same hereinas it forms no part of the invention in the present application.

In this drawing a is a rock crusher of any suitable kind arranged todischarge into a rotating sieve Z) the finely crushed material fromwhich passes down into a rotating gas fired roasting furnace c. Thislatter is provided with a number of conductors 0 through which a currentis passed from the external wires 0 by means of brushes 0 and externalcontact making rings 0, 0 which 4 are connected through the walls of thefurnace with the conductors c. The ore which is tumbled over and over bythe rotation of the furnace is thusbrought into contact with the liveconductors. It is in this furnace that the ore may be treated later toconvert the base metals into sulfates or chlorids with the accompanimentof spraying or spraying with the. salt addition as the case requlres.Such furnace is connected to a condenserd in which the arsenic and otherfumes may be condensed. From the furnace the ore is discharged to asuitable electric concentrator e in which the magnetic iron is separatedfrom it, the remaining body of ore being-dischar ed into the agitator f.This may consist o a tank having an outer cas-. ting f of wood or metalanda glass or earthenware lining f Depending into same is a pipe fhaving branches fwhic'h' are open at their lower ends and .0 not 'entendto the bottom of the tank. The pipe f connects with a pipe f from asource'of hot air under pressure and a ipe f to a supply of oxygenorenriched aiFi. At" the bottom of theftank'fis" an opening covered by asolid plate orfdoor, and a remo'vablefilter screen fl through whichlatter when the door is opened or removed the" co solutionpasses intothe electrodepos t ngtanks g and throu hQWhich also'the cyan d solutiontanks being supp ed from a common launderz' provlded'with suitablegatej. When exhausted ore.

. subsequent can pass toa: tank k'these two In the astier orescontaining cobalt and silyer, thetr'e'atment would beitheqsame as}containing zincfand silver thatis the arsenic fwould be fumed jo'fii'thelore}; sulfu'ricj' eated in" for ores heated iri the lfurnace witlrafjacid; sprayand then'reinoyed an iii the 'electr cjconcentrator orconcentrators recover first the iron and thenth cobalt'as' in the caseof the zinc. The ore is then reand treated in the agitator ceases turnedto the furnace, sprayed with sulfuric acid and salt and heated untilchlorid of silver is formed and the charge is removed by boiling withthe hot blast. The silver is recovered by known methods from the chloridsolution.

thus formed.

What I claim is 1. The herein described process of treating orescontaining iron, and other metals which consists in first removing theiron therefrom then bringing a metal contained therein into the form ofa solution by boiling same in water and a suit-able acid by means of ahot air blast and then recovering such metal.

2. The herein described process of treating ores containing iron, andother metals which consists in roasting same, then removing irontherefrom thenboiling same in water and a suitable acid by means of ahot air blast to form a solution of a metal therein and then recoveringsuch metal.

3. The herein described process of treating ores containing iron,arsenic, and other metals which consists in roasting same condensingarsenic fumes then removing iron therefrom in the state of iron sand,then boiling same in water and sulfuric acid by means of a hot air blastto form a solution of a metal therein and then recovering such metal.

4. The herein described process of treating ores containing iron copperand other metals which consists in roasting same treating themduringsuch roasting with sulfuric acid and water to bring the copperinto the condition of a sulfate, then removing the iron therefrom in thestate of iron sand then boiling same in water means of a hot air blastto form a solution of a metal therein and. then recovering such metalj5. The herein described process of treating sulfid ores containing iron,precious and other metals which consists in roasting same and at thesame time converting certain metal contents into sulfates, then removingthe iron therefrom in the state of iron sand, then and sulfuric acid byboiling the ore so separated with water and sulfuric acid and a hot airblast to form a solution of a metal therein then removing such solution,treating same for the recovery of the metal and then treating the oreresidue to extract the precious metal.

6. The herein described process of treating ores containing iron,precious, and other metals which consists in first removing the irontherefrom, thenbringing certain of the metals contained therein into theform of a solution, removing such solution, and boiling the ore residueby means of a hot blast in a cyanid solution to recover the preciousmetal.

7. The herein described process of treating sulfid ores containing iron,precious and other metals which consists in roasting same and at thesame time converting certain metal contents into sulfates, then removinthe iron therefrom in the state of iron san then boiling the ore soseparated with water and sulfuric acid and a hot air blast, to form asolution of a metal therein then removing such solution, treating samefor the recovery of the metal, washing the ore residue and then treatingwith a cyanid solution in the presence of enriched air to extract theprecious metal.

8. The herein described process of treating sulfid ores containing iron,precious and other metals which consists in roasting the same and at thesame time converting certain metal contents into sulfates, then removingthe iron therefrom in the state of iron sand then boiling the ore soseparated with water and sulfuric acid and a hot air blast to form asolution of the sulfate, then removing such solution, treating same forthe recovery of the metal, washing the ore residue and then treatingwith a cyanid solution with the addition of a hot blast and in thepresence of enriched air.

In witness whereof I have set my hand in the presence of two subscribingwitnesses.

ELIZABETH BARNSTON PARNELL.

Witnesses:

B. WnsrAcor-"r,

H. D. JAMESQN.

